The technology of fabricating semiconductor integrated circuits has advanced with regard to the number of transistors, capacitors and other electronic devices which can be fabricated on a single integrated circuit chip. This increasing level of integration has resulted in large part from a reduction in the minimum feature sizes of the integrated circuits and an increase in the number of layers which make up the integrated circuit. Today's design features, generally referred to as “sub-micron” have dropped below 0.25 microns. The manufacture of integrated circuit components having this reduced size and the need to reduce production steps has placed new demands on all aspects of their production including the removal of resists and related materials with chemical stripper solutions.
Semiconductor devices for semiconductor integrated circuits or liquid crystal displays are commonly produced by a process including the steps of coating a substrate with one or more layers of polymeric resist materials to provide a resist film; patterning the photosensitive resist film by exposure to light and subsequent development; etching exposed portions of the substrate using the patterned resist film as a mask to form minute circuits; and removing the resist film from the inorganic substrate. Alternatively, after forming minute circuits, the post etch residues can be ashed and the remaining resist residues removed from the substrate with a post etch residue remover. This portion of circuit fabrication is referred to as the back-end-of-line (BEOL) fabrication. What is needed is a BEOL stripper solution which can remove remaining photoresists and post etch residues in a single step.
A superior BEOL stripper solution should: (a) quickly and cleanly remove resist residues, etch residues and related materials at moderate to low temperatures without requiring a final ashing or post etch removal step, (b) have an acceptable effect on the all exposed components, particularly the underlying low or ultra low-κ dielectric and metals, (c) have a substantial capacity to dissolve and/or suspend resist and/or post etch residue to forestall precipitation and/or re-deposition of solid onto the wafer necessitating the early disposal of the stripper solution, (d) be safe to use in a manufacturing environment, (e) have an acceptable shelf-life and (f) be backward compatible with lower technology nodes. A superior BEOL stripper solution should also quickly remove resist residues in a rework process without substrate damage. Finally, superior stripper solutions should exhibit minimal toxicity. This present disclosure addresses and resolves these needs.